The present invention generally relates to an apparatus and method for making a unitary construction element or shape having an insulating or thermal barrier member therein, commonly referred to as a thermal barrier or thermobreak extrusion or shape, which can be employed in the construction of windows, doors, frames therefor, curtain walls and the like.
The invention particularly relates to an apparatus for making a unitary construction element, wherein an insulating member is joined to a metal member or members by a crimping or stitching operation.
With the advent of metal construction used in making windows, doors, frames therefor, curtain walls and the like, problems of heat conduction and water condensation have arisen. The use of aluminum or other metals caused a greater transfer of heat between wall elements than had heretofore taken place in earlier types of construction. To solve this problem, some type of insulating or thermal break construction was essential. Accordingly, a variety of thermal barrier or thermobreak constructions and methods and apparatuses for making such constructions have been developed.
One type of construction which has achieved some degree of success is one in which the insulating material is poured, flowed, foamed, and formed in place. U.S. Pat. Nos. 3,204,324; 3,332,170; 3,393,487; 3,624,885 (Re. 28,084 and Re. 28,086); 3,634,565; and 3,823,524 are illustrative of such type of construction. Of these, 3,204,324 is representative of a method of making a thermal barrier construction element or insulating construction, wherein a metal shape having a generally U-shaped channel therein is filled with a flowing resinous insulating composition; the composition is cured, and subsequently a portion of the metal member or web forming the base of the channel is removed. No. 3,823,524 relates to a similar method but employs a web member which extends convexly between the structural member forming the channel. Both of these methods require the use of a liquid resinous composition which is subsequently cured or hardened. No. 3,393,487 discloses a somewhat more complicated process for making a thermal insulating joing construction and also utilizes a liquid plastic material. In such process, two separate elongated metal shapes are spaced apart and fastened together with a solid first insulating member. The two shapes and the first insulating member provide a channel in which a second thermal insulating member is flowed therein. Upon solidification of the latter, the metal and insulating members are locked together as an integral unit.
Of the more common types of thermal barrier constructions, two metal members are joined together by a solid insulating member. These constructions encompass a wide variety of insulating and/or plastic shapes and metal shapes. Illustrative of these are U.S. Pat. Nos. 2,835,360; 3,093,217; 3,099,337; 3,289,377; 3,436,884; 3,487,580; 3,600,857; and 3,916,503. In one of the more basic of this type of construction, for example, in 2,835,360, two metal members are joined together and spaced apart by an overlapping insulating member. In 3,916,503, simple mechanical means are employed to join the metal members with an insulating member. No. 3,600,857 is representative of more complex shapes of insulating and metal members.
In a particular type of the foregoing more common type of thermal barrier constructions, metal and insulating members are mechanically joined together by deformation of the metal members or by crimping or stitching the metal members on the insulating member. Representative of such a joining method are U.S. Pat. Nos. 3,114,179; 3,411,995; 3,420,026; 3,517,472; and 3,903,217 and Swiss Pat. No. 320,988 (same as British Pat. No. 768,499). For example, 3,420,026 discloses several types of thermal insulating members and methods of making them. In one type, two separate metal members are mechanically joined to a central insulating member by crimping or deformation of groove means or projections on the metal members. In one particular type of thermal break construction, the insulating member is in the shape of a Maltese cross in cross-section. In another embodiment, the insulating member is made from a thermoplastic material and a portion thereof is heated to cause melting and flow of the plastic into an associated groove means formed by the two metal members. Upon cooling of the plastic, the metal and plastic member are unitarily joined together. No. 3,517,472 also illustrates a mechanical joining process similar to that of the former and additionally represents the use of a plastic or insulating member which expands upon heating. The Swiss patent discloses several types of window or door frames, one of which employs a crimp system using two separate metal extrusions having a pair of flanges thereon which form grooves for receiving a plastic rod. After the plastic rod or thermal barrier member is introduced into the grooves, the flanges are pressed towards the plastic rod or crimped thereon so that they are flush with the sides of the rod.
Other types of thermal break or insulated window or wall constructions are illustrated by U.S. Pat. Nos. 2,654,920; 3,055,468; 3,289,377; 3,411,254; and 3,446,801. For example, No. 3,411,254 provides a plastic thermobreak which utilizes a plastic locking strip which contains a heat actuated blowing agent to join two separate metal shapes. After assembly of the two metal shapes and the plastic strip, the unit is heated to expand the plastic into tight engagement with the two metal members.
U.S. Pat. No. 3,815,216 illustrates still another method of manufacturing a thermal break construction element and employs a metal extrusion which has a removable interior section which is subsequently removed to separate the extrusion into two metal members. While maintaining the separate metal members spaced apart, a plastic material is inserted therebetween. The construction element can be made in a continuous operation.
Of these various types of thermal break constructions, the system of crimping or stitching has enjoyed considerable commercial success. In such systems, crimping is often done manually or by simple mechanical means. Such means are of course relatively slow and have limited flexibility. One current stitching system consists of a feeder for inserting straight lengths of vinyl or other suitable plastic insulating members in the metal members. Rollers are employed to provide crimping of the metal flanges on the insulating or plastic member. Conventionally, two rollers or wheels are required to crimp the flanges. One roller must actually bend the metal flanges on the insulating member while the other roller must back-up or hold the metal extrusion in the correct position for joining metal and plastic members. To accomplish the crimping action, clear access must be available on both sides of the plastic member on which crimping of the metal members occurs. In some cases, a small wheel or support is laterally employed to serve as a back-up. The size of the support and the forces required to obtain a tight joint create a number of operating problems. The types of shapes or extrusions which can be used in this method are extremely limited. Finished parts have to be removed by hand after the stitching or crimping operation is completed.
It is therefore a primary object of the present invention to provide a crimp or stitching system or method of making thermal barrier extrusions which overcomes the disadvantages of prior art systems and which can be used with a wide variety of metal shapes or extrusions.
An important object of the invention is to provide a complete machinery line assembly or apparatus for rapidly and efficiently manufacturing thermal barrier or thermobreak extrusions shapes or members.
Another object of the present invention is to provide a stitcher or crimping machine which can quickly and easily be adjusted to handle a wide variety of metal shapes.
Still another object of the invention is to provide an elongated guide box which is adapted to handle a large number of metal shapes or extrusions of different configurations.
Other objects and advantages of the present invention will become more readily apparent from a consideration of the description and drawings hereinafter.